Heat a Dutch oven coated with cooking spray over medium-high heat. Add chicken; sauté 2 minutes. Add garlic; cook 15 seconds.
Stir in potato, mushrooms, and next 4 ingredients. Bring to a boil; cover, reduce heat, and simmer 20 minutes or until potato is tender, stirring occasionally. Remove from heat; stir in sour cream and salt. Sprinkle each serving evenly with parsley.